Angiogenesis
In an adult, two types of blood vessels can potentially be found. The normal blood vessel is a resting, quiescent, fully developed vessel. A second form, a proliferating or developing blood vessel, occurs rarely during the normal life cycle (only in early development and reproduction, e.g., menstrual cycle and pregnancy). In contrast, the process of angiogenesis, the proliferation and development of new blood vessels, often occurs in wound healing and in pathological processes, e.g., tumor growth. Angiogenesis is a complex process involving many stages, including extracellular matrix remodeling, endothelial cell migration and proliferation, capillary differentiation, and anastomosis. All detectable solid tumors (tumors over 2 mm in diameter) exploit angiogenesis to supply the needed blood to proliferating tumor cells. Studies have demonstrated that the level of vascularization in a tumor is strongly associated with metastasis in melanoma, breast, and lung carcinomas. See R. Bicknell, “Vascular targeting and the inhibition of angiogenesis,” Annals of Oncology, vol. 5, pp. 45-50 (1994).
Angiogenesis inhibitors have been suggested to intervene into neoplastic processes. See G. Gasparini, “The rationale and future potential of angiogenesis inhibitors in neoplasia,” Drugs, vol. 58, pp. 17-38 (1999). The inhibitory agents block angiogenesis, thereby causing tumor regression in various types of neoplasia. Known therapeutic candidates include naturally occurring angiogenic inhibitors (e.g., angiostatin, endostatin, platelet factor-4), specific inhibitors of endothelial cell growth (e.g., TNP-470, thalidomide, interleukin-12), agents that neutralize angiogenic molecules (e.g., antibodies to fibroblast growth factor or vascular endothelial growth factor), suramin and its analogs, tecogalan, agents that neutralize receptors for angiogenic factors, agents that interfere with vascular basement membrane and extracellular matrix (e.g., metalloprotease inhibitors, angiostatic steroids), and anti-adhesion molecules (e.g., antibodies such as anti-integrin alpha v beta 3). See L. Rosen, “Antiangiogenic strategies and agents in clinical trials,” Oncologist, vol. 5, supplement 1, pp. 20-27 (2000).
Abnormal angiogenesis occurs when improper control of angiogenesis causes either excessive or insufficient blood vessel growth. Excessive blood vessel proliferation favors tumor growth and development of distant metastases, blindness, skin disorders such as psoriasis, and rheumatoid arthritis. Diseases or conditions that have been associated with undesired vascularization include, for example, diabetic retinopathy, retinopathy of prematurity, corneal graft rejection, neovascular glaucoma, retrolental fibroplasia, epidemic keratoconjunctivits, Vitamin A deficiency, atopic keratitis, contact lens overwear, superior limbic keratitis, pterygium keratitis sicca, sjogren's syndrome, acne rosacea, phylectenulosis, syphilis, myobacterial infections, lipid degeneration, chemical bursn, bacterial ulcers, fungal ulcers, Herpes simplex infections, Herpes zoster infections, protozoan infections, Kaposi's sarcoma, Mooren's ulcer, Terrien's marginal degeneration, marginal keratolysis, trauma, rheumatoid arthritis, systemic lupus, polyarteritis, Wegener's sarcoidosis, scleritis, Stevens-Johnson disease, radial keratotomy, macular degeneration, sickle cell anemia, sarcoidosis, pseudoxanthoma elasticum, Paget's disease, vein occlusion, carotid obstructive disease, chronic uveitis, chronic vitritis, Lyme's disease, Eales' disease, Behcet's disease, myopia, optic pits, Stargardt's disease, pars planitis, chronic retinal detachment, hyperviscosity syndromes, toxoplasmosis, post-laser complications, abnormal proliferation of fibrovascular or fibrous tissue, hemangiomas, Osler-Weber-Rendu disease, solid tumors, blood borne tumors, acquired immune deficiency syndrome, ocular neovascular disease, age-related macular degeneration, osteoarthritis, diseases caused by chronic inflammation, Crohn's disease, ulceritive colitis, tumors of rhabdomyosarcoma, tumors of retinoblastoma, tumors of Ewing's sarcoma, tumors of neuroblastoma, tumors of ostteosarcoma, leukemia, psoriasis, atherosclerosis, pemphigoid, infections causing retinitis or choroiditis, presumed ocular histoplasmosis, Best's disease, proliferative vitreoretinopathy, Bartonellosis, acoustin neuroma, neruofibroma, trachooma, pyogenic granulomas, obesity, corneal neovascularization, malignant tumor growth beyond 2 mm, benign tumors, benign functional endocrine tumors, arterial/venous malformations, primary hyperparathyroidism, secondary hyperparathyroidism, and tertiary hyperparathyroidism. Other angiogenic-related diseases may include, for example, diseases associated with rubeosis (neovascularization of the angle), and diseases caused by abnormal proliferation of fibrovascular or fibrous tissue, including all forms of proliferative vitreoretinopathy. Any disease having a known angiogenic counterpart could potentially be treated with an anti-angiogenic factor, e.g., psoriasis. See D. Creamer et al., “Overexpression of the angiogenic factor platelet-derived endothelial cell growth factor/thymidine phosphorylase in psoriatic epidermis,” Br. J. Dermatol., vol. 137, pp. 851-855 (1997).
Angiogenesis is a prominent contributor to solid tumor growth and the formation of distant metastases. Several experimental studies have concluded that primary tumor growth, tumor invasiveness, and metastasis all require neovascularization. The process of tumor growth and metastasis is complex, involving interactions among transformed neoplastic cells, resident tissue cells (e.g., fibroblasts, macrophages, and endothelial cells), and recruited circulating cells (e.g., platelets, neutrophils, monocytes, and lymphocytes). A possible mechanism for the maintenance of tumor growth is an imbalance, or disregulation, of stimulatory and inhibitory growth factors in and around the tumor. Disregulation of multiple systems allows the perpetuation of tumor growth and eventual metastasis. Angiogenesis is one of many systems that is disregulated in tumor growth. In the past it has been difficult to distinguish between disregulation of angiogenesis and disregulation of other systems affecting a developing tumor. Another complicating factor is that aggressive human melanomas mimic vasculogenesis by producing channels of patterned networks of interconnected loops of extracellular matrix, in which red blood cells, but not endothelial cells, are detected. See A. J. Maniotis et al., “Vascular channel formation by human melanoma cells in vivo and in vitro: Vasculogenic mimicry,” Am. J. Pathol., vol. 155, pp. 739-52 (1999). These channels may facilitate perfusion of tumors, independent of perfusion from angiogenesis.
A tumor cannot expand beyond approximately 2 mm without a blood supply to provide nutrients and remove cellular wastes. Tumors in which angiogenesis is important include solid tumors, and benign tumors including acoustic neuroma, neurofibroma, trachoma, and pyogenic granulomas. Inhibiting angiogenesis could halt the growth and potentially lead to regression of these tumors. Angiogenic factors have been reported as being associated with several solid tumors, including rhabdomyosarcoma, retinoblastoma, Ewing sarcoma, neuroblastoma, and osteosarcoma.
Angiogenesis has also been associated with some non-solid tumors, including blood-born tumors such as leukemias, various acute or chronic neoplastic diseases of the bone marrow marked by unrestrained proliferation of white blood cells, usually accompanied by anemia, impaired blood clotting, and enlargement of the lymph nodes, liver, and spleen. It is believed that angiogenesis may play a role in the abnormalities in the bone marrow that give rise to leukemias and multiple myelomas.
Anti-angiogenic factors inhibit tumor growth beyond 2 mm by inhibiting the angiogenic response and thus inhibiting blood vessel growth to the tumor. Although angiogenesis in a tumor may begin at an early stage, a tumor requires a blood supply to grow much beyond about 2 mm. Up to 2 mm diameter, tumors can survive by obtaining nutrients and oxygen by simple diffusion. Most anti-angiogenic factors are not cytotoxic, i.e., capable of killing the tumor cells directly. Small tumors of a size about 1 mm3 can be effectively inhibited and destroyed by factors, either endogenous or exogenous, that stimulate the immune system. It is generally accepted that once a tumor has reached a critical size, the immunological system is no longer able to effectively destroy the tumor; i.e., there is a negative correlation between tumor size and immune competence. See A. K. Eerola et al., “Tumour infiltrating lymphocytes in relation to tumour angiogenesis, apoptosis,” Lung Cancer, vol. 26, pp. 73-83 (1999); and F. A. Wenger et al., “Tumor size and lymph-node status in pancreatic carcinoma—is there a correlation to the preoperative immune function?,” Langenbecks Archives of Surgery, vol. 384, pp. 473-478 (1999). Early adjuvant use of an effective anti-angiogenic agent to preclude development of tumor metastases beyond 1 to 2 mm3 may allow more effective tumor attack and control by the body's immunological mechanisms. In addition, prolonged adjuvant use of a non-toxic angiogenic inhibitor may prevent tumor dissemination by blocking the growth of vessels required for the transport of tumor cells that would form metastatic foci.
Angiogenesis has also been implicated in obesity. Several mice strains, both young and aged animals, used as obesity models treated with anti-angiogenic agents lost weight. See M. A. Rupnick et al., “Adipose tissue mass can be regulated through the vasculature,” PNAS, vol. 99, pp. 10730-10735 (2002). This same study also found that adipose tissue mass was reduced by the anti-angiogenic compounds.
New anti-angiogenic factors are needed, in particular, compounds that not only inhibit new angiogenic growth, but also that degrade existing capillary networks. Very few anti-angiogenic factors have been reported to diminish existing capillary networks.
Chinese Blackberry, Rubus suavissimus S. lee
Rubus suavissimus S. Lee, a perennial shrub, Chinese blackberry, is one of some 62 species in the genus Rubus of the Rosaceae family. It is widely distributed in the southwest of China but flourishes in Guangxi Autonomous Region. Leaves of Chinese blackberry have long been used in southern China as a tea due to its sweet taste, thus the Chinese name Tiancha or Sweet Leaf Tea. The sweet taste is due to the presence of dipterpene glucosides in the leaves, one of which is rubusoside, reaching a concentration of over 5% (w/w). See T. Tanaka et al., “Rubusoside (β-D-glucosyl ester of 13-O-β-D-glucosyl-steviol), a sweet principle of Rubus chingii Hu (Rosaceae),” Agric. Biol. Chem., vol. 45, pp. 2165-2166 (1981); and T. Seto et al., “β-Glucosyl esters of 19α-hydroxyursolic acid derivatives in leaves of Rubus species,” Phytochemistry, vol. 23, pp. 2829-2834 (1984). There were other diterpene glucosides found in the leaves, e.g., suavioside A and suaviosides B, C1, D2, F, G, H, I, and J. See S. Hirono et al., “Sweet and bitter diterpene-glucosides from leaves of Rubus suavissimus,” Chem. Pharm. Bull., vol. 38, pp. 1743-1744 (1990); W.-H. Zhou et al., “A new sweet diterpene-glucoside in leaves of Rubus suavissimus, “ ” Acta Botanica Sinica, vol. 34, pp. 315-318 (1992); and K. Ohtani et al., “Minor diterpene glycosides from sweet leaves of Rubus suavissimus,” Phytochemistry, vol. 31, pp. 1553-1559 (1992). Further chemical analyses over the leaves of thirty-nine other Rubus spp. revealed that the presence of diterpene glycosides is only limited to the leaves of R. suavissimus and R. chingii, whereas glucosyl 19α-hydroxyuresana-type triterpenes are more common as constituents in the leaves of Rubus spp. See F. Gao et al., “19α-hydroxyursane-type triterpene glucosyl esters from the roots of Rubus suavissimus S. Lee,” Chem. Pharm. Bull., vol. 33, pp. 37-40 (1985)
In southern China, especially in Guangxi Autonomous Region, the leaves of R. suavissimus are used not only as tea and a food additive, but also as herbal medicines thought to nourish the kidneys and lower blood pressure. See P.-F. Huang et al., “Comprehensive utilization of Rubus suavissimus S. Lee,” Guangxi Huagong, vol. 31, pp. 24-25 (2002). The leaf of Chinese blackberry has also been said to help with fever, to relieve stress on the lungs, to reduce the secretion of phlegm, and to relieve coughs. See Y. Ono, “The health beneficial effects of Tien-cha (Rubus suavissimus tea) and its applications,” Food Style 21, vol. 6, pp. 77-80 (2002). Recent studies indicated an anti-inflammatory and anti-allergy effect. See U. Kotaro, “Antiallergy action of Rubus suavissimus,” Shokuhin Kogyo, vol. 40, pp. 52-59 (1997); K. Nakahara, “Anti-allergic activity of Tiencha and oolong tea polyphenols,” Food Style 21, vol. 2, pp. 45-49 (1998); and K. Nakahara et al., “Anti-allergic composition containing GOD-type ellagitannin as active ingredient,” European Patent Application No. 727218 (1996).
Black Raspbery, Rubus occidentalis 
Rubus occidentalis or black raspberry is a perennial shrub native to North America. The berries are juicy and black, with multiple drupes, and ripen from June to July. When picked the berries separate from their fleshy core, forming a hollow shell compared to the stick core on blackberries. Oregon is the major producer of black raspberry, producing 1.9 million pounds of fresh berries in 1996.
The berries are rich in anthocyanins, pectin, fruit acids, and vitamins A, B1 and C. Anthocyanins are widely distributed in plants, and are responsible for the pink, red, purple and blue hues seen in many flowers, fruits and vegetables. They are water-soluble flavonoid derivatives, which can be glycosylated and acylated. Increased interest is seen in anthocyanins due to their activity as antioxidants, which act as scavengers to free radicals thus avoiding oxidative stress to tissues and cells. See J. M. Kong et al., “Analysis and biological activities of anthocyanins,” Phytochemistry, vol. 64(5), pp. 923-33 (2003). The antioxidant activities of the anthocyanins may account for some of beneficial effects derived from the consumption of fruits and vegetables high in anthocyanins against cardiovascular and other diseases.
Black raspberry is a common food item, and also used by USDA inspectors as a natural “ink” to stamp commercial meat products. Recently, the antioxidant activity, corresponding to the high anthocyanin and phenolic content, of black raspberry has been reported. See L. Wada L et al., “Antioxidant activity and phenolic content of Oregon caneberries,” J. Agric. Food Chem., vol. 50(12), pp. 3495-500 (2002); and S. Y. Wang et al., “Scavenging capacity of berry crops on superoxide radicals, hydrogen peroxide, hydroxyl radicals, and singlet oxygen,” J. Agric. Food Chem., vol. 48(11), pp. 5677-84 (2000). A black raspberry extract was found to inhibit tumor development in rodents, possibly by impairing signal transduction pathways leading to activation of activated protein 1 and nuclear factor kappa B and by inhibiting the activity of cyclooxygenase. See C. Huang et al., “Inhibition of benzo(a)pyrene diol-epoxide-induced transactivation of activated Protein 1 and Nuclear Factor B by black raspberry extracts,” Cancer Research, vol. 62, pp. 6857-6863 (2002); and N. P. Seeram et al., “Cyclooxygenase inhibitory and antioxidant cyanidin glycosides in cherries and berries,” Phytomedicine, vol. 8(5), pp. 362-9 (2001). The active antioxidant compounds in black raspberry are known to be orally bioavailable. See T. K. McGhie et al., “Anthocyanin glycosides from berry fruit are absorbed and excreted unmetabolized by both humans and rats,” J. Agric. Food Chem., vol. 51(16), pp. 4539-4548 (2003). However, dietary intervention often fails in clinical studies, probably due to the low levels and huge variations of the unidentified active compounds in the berry diet tested. See B. L. Halvorsen et al., “A systematic screening of total antioxidants in dietary plants,” J. Nutr., vol. 132(3), pp. 461-71 (2002).
Earlier studies suggested that a component(s) in black raspberry influenced the metabolism of N-nitrosomethylbenzylamine. See L. A. Kresty et al., “Inhibitory effect of lyophilized black raspberries on esophageal tumorigenesis and O6-methylguanine levels in the F344 rat,” Proc. Annu. Meet. Am. Assoc. Cancer Res., vol. 39, p. A120 (1998). This chemopreventive effect has primarily been attributed to the ellagic acid in black raspberries, which has been shown to inhibit cancers induced in rodents by several carcinogens. The chemopreventive activity of ellagic acid and black raspberry fractions was assessed in a Syrian hamster embryo cell transformation model, finding that ellagic acid and a methanol fraction of black raspberry produced a dose-dependent decrease in transformation, possibly through interfering with the uptake, activation, and/or detoxification of the carcinogenic benzo[a]pyrene and/or the intervention of DNA binding and DNA repair. See H. Xue et al., “Inhibition of cellular transformation by berry extracts,” Carcinogenesis, vol. 22(2), pp. 351-6 (2001).
Pomegranate Fruit, Punica granatum L.
Pomegranate, Punica granatum L., is of the family Punicaceae and is called the Wonderful cultivar. The fruits are commercially available. A number of studies have reported that pomegranate fruit and its methanol extract possess antioxidant compounds. See M. I. Gil et al., “Antioxidant activity of pomegranate juice and its relationship with phenolic composition and processing,” J. Agric. Food Chem., vol. 48(10), pp. 4581-9 (2000); R. P. Singh et al., “Studies on the antioxidant activity of pomegranate (Punica granatum) peel and seed extracts using in vitro models,” J. Agric. Food Chem., vol. 50(1), pp. 81-6 (2002); and International Application Nos. WO 00/64472 and WO 2004/022028. Anthocyanins and hydrolysable tannins in the form of ellagic acid and derivatives were detected in the juice. Also pomegranate fruit wine demonstrated antioxidant activity and inhibited nuclear factor kappa B. See S. Y. Schubert et al., “A novel mechanism for the inhibition of NF-kappaB activation in vascular endothelial cells by natural antioxidants,” FASEB J., vol. 16(14), pp. 1931-3 (2002). An organic extract of pomegranate peel fed to albino Wistar rats inhibited oxidative enzymes such as catalase, peroxidase and superoxide dismutase, but increased lipid peroxidation. See K. N. Chidambara Murthy et al., “Studies on antioxidant activity of pomegranate (Punica granatum) peel extract using in vivo models,” J. Agric. Food Chem., vol. 50(17), pp. 4791-5 (2002). Histopathological studies of the liver demonstrated a protective effect the methanolic extract of pomegranate peel on hepatic architecture. The antioxidant activity displayed by the pomegranate peel extract may be due to gallotannins and a range of prodelphinidins as well as anthocyanidins. See G. W. Plumb et al., “Antioxidant properties of gallocatechin and prodelphinidins from pomegranate peel,” Redox Rep., vol. 7(1), pp. 41-6 (2002); and Y. Noda et al., “Antioxidant activities of pomegranate fruit extract and its anthocyanidins: delphinidin, cyanidin, and pelargonidin,” J. Agric. Food Chem., vol. 50(1), pp. 166-71 (2002). Pomegranate polyphenols were found to protect low-density lipoprotein against cell-mediated oxidation via two pathways: direct interaction of the polyphenols with the lipoprotein and/or an indirect effect through accumulation of polyphenols in arterial macrophages. See M. Aviram et al., “Pomegranate juice flavonoids inhibit low-density lipoprotein oxidation and cardiovascular diseases: studies in atherosclerotic mice and in humans,” Drugs Exp. Clin. Res., vol. 28(2-3), pp. 49-62 (2002). The antioxidative and antiatherogenic effects of pomegranate polyphenols were demonstrated using an in vitro assay in humans and in atherosclerotic apolipoprotein E deficient mice. See M. Kaplan et al., “Pomegranate juice supplementation to atherosclerotic mice reduces macrophage lipid peroxidation, cellular cholesterol accumulation and development of atherosclerosis,” J. Nutr., vol. 131(8), pp. 2082-9 (2001).
Pomegranate seed oil (5%) was tested in a mouse model for its chemopreventive activity against cancer and found that it significantly decreased tumor incidence, decreased the number of tumor sites, and decreased 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ornithine decarboxylase activity. See J. J. Hora et al., “Chemopreventive effects of pomegranate seed oil on skin tumor development in CD1 mice,” J. Med. Food., vol. 6(3), pp. 157-61 (2003); and International Application No. WO 02/094303. Components of pomegranate fruit (fermented juice, aqueous pericarp extract, and cold-pressed or supercritical CO2-extracted seed oil) displayed various degrees of anti-proliferative effects on a human breast cancer cell line and the activity was correlated with polyphenols in these fractions. See N. D. Kim et al., “Chemopreventive and adjuvant therapeutic potential of pomegranate (Punica granatum) for human breast cancer,” Breast Cancer Res. Treat., vol. 71(3), pp. 203-17 (2002).
Pomegranate extract has also been shown to be anti-inflammatory. Combined with the extract of Centella asiatica, pomegranate extract was able to reduce clinical signs of chronic periodontitis. See G. Sastravaha et al., “Adjunctive periodontal treatment with Centella asiatica and Punica granatum extracts. A preliminary study,” J. Int. Acad. Periodontol., vol. 5(4), pp. 106-15 (2003). Pomegranate extract used topically reduced candidiasis associated with denture stomatitis. See L. C. Vasconcelos et al., Use of Punica granatum as an antifungal agent against candidosis associated with denture stomatitis,” Mycoses, vol. 46(5-6), vol. 192-6 (2003).
Absorption into blood stream of ingested pomegranate ellagitannins in the form of punicalagin is around 3 to 6%, indicating that a large amount of the extract has to be ingested for the active components to be bioavailable. See B. Cerda et al., “Evaluation of the bioavailability and metabolism in the rat of punicalagin, an antioxidant polyphenol from pomegranate juice,” Eur. J. Nutr., vol. 42(1), pp. 18-28 (2003).
Using a human umbilical vein endothelial cell (HUVEC) model, pomegranate seed oil and fermented juice polyphenols were demonstrated to be anti-angiogenic, inhibiting proliferation of the endothelial cells, myometrial cells, amniotic fluid fibroblasts, and tubule formation. See M. Toi et al., “Preliminary studies on the anti-angiogenic potential of pomegranate fractions in vitro and in vivo,” Angiogenesis, vol. 6, pp. 121-128 (2003); and International Application No. 2004/019961. These preparations also showed downregulation of vascular endothelial growth factor, which is required during the processes of angiogenic initiation and growth. In a test using the chicken chorioallantoic membrane model, pomegranate fermented juice polyphenols were found to inhibit angiogenesis, but the pomegranate pericarp polyphenols were not active. This suggests different inhibitory activities displayed by different sources of the same class of polyphenols. See Toi et al., 2003.
Gallic Acid
Gallic acid or 3,4,5-trihydroxy benzoic acid, is a colorless crystalline organic acid found in many plants. The list of plants that have been shown to contain gallic acid include: Abrus prccatorius L.; Acacia catechu (L.) Willd.; Ampelopsis brevipedunculata; Ampelopsis japonica; Coriaria sinica Maxim.; Cornus officinalis Sieb. et Zucc. (Dogwood); Cotinus coggygria Scop. (Smokebush); Daucus carota L. var. Sativa DC.; Iridium stephanianum Willd.; Eucalyptus robusta Sm.; Euonymus bungeanus Maxim. (Winterberry Euonymus); Euphorbia humifusa Wild. (Wolf's milk); Geranium pratense L.; Geranium wilfordii Maxim. (Heron's Bill); Juglans regia L.; Loropetalum chinensis (R. Br.) Oliv. (Chinese fringe tree); Lythrum salicaria L.; Malus spp. (Apple); Mangifera indica L. (Mango); Macrocarpium officinale Sieb. et Zucc.; Passiflora caerulea L.; Pharbitis nil (L.) Choisy; Phyllanthus emblica L.; Pistacia chinensis Bge.; Platycarya longipes Wu.; Platycarya strobilacea Sieb. et Zucc. (Australia cheesewood); Polygonum aviculare L.; Polygonum bistorta l. (Bistort); Psidium guajava L. (guava); Quercus infectoria Oliver; Rheum officinale Baill.; Rheum palmatum L. (Rhubarb); Rheum tanguticum Maxim. Ex Reg.; Rhus chinensis Mill. (Chinese sumac gallnut); Rhus potaninii Maxim. (Sumac gallnut); Rosa chinensis Jacq. (Mini rose); Rosa rugosa Thunb. (Rose); Rubus ulmifolius; Rumex japonicus Houtt. (Japanese dock); Sanguisorba officinalis L. (Burnet); Sapium sebiferum (L.) Roxby.; Syzygium cumini (L.) Skeels; Tamarix chinensis Lour.; Terminalia chebula Retz. (Medicine terminalia); Tetrastigma hypoglaucum Planch.; and Tussilago farfara L. See U.S. Pat. No. 6,444,236; Colored Illustrations of Chinese Traditional and Herbal Ordinary Drugs in China, Wu Jianrong and Quiz Dewey, editors; Huizhou Technology and Science Press, Guiyang, China (1993); Z. Liu et al., Encyclopedia of Woody Medicinal Plants of China, CD-ROM, Academic Services Associates, Inc., Seattle, Wash. (2000); D. Liu et al., “Studies on Chemical Constituents from Tetrastigma Hypoglaucum,” Chinese Trad. And Herbal Drugs, vol. 34, pp. 4-6 (2003); L. Panizzi et al., “In Vitro Antimicrobial Activity of Extracts and Isolated Constituents of Rubus Ulmifolins,” J. Ethnopharmacol., vol. 29, pp. 165-8 (2002); Encyclopedia of Traditional Chinese Medicine, Shanghai S&T Press (1986); and K. Wolfe et al., “Antioxidant activity of apple peels,” J. Agric. Food Chem., vol. 51, pp. 609-14 (2003).
Since gallic acid has hydroxyl groups and a carboxylic acid group in the same molecule, two molecules can react to form an ester, digallic acid. Gallic acid is usually obtained by the hydrolysis of tannic acid with sulfuric acid. Gallic acid is known to be a strong natural antioxidant. See K. Polewski et al., “Gallic acid, a natural antioxidant, in aqueous and micellar environment: spectroscopic studies,” Current Topics in Biophysics, vol. 26, pp. 217-227 (2002).
Gallic acid is wide-spread in plant foods and beverages such as tea and wine and has been shown to be one of the anticarcinogenic polyphenols present in green tea. Gallic acid has been shown to display selective cytotoxicity against tumor cells, and to induce apoptosis in tumor cells. See K. Isuzugawa et al., “Different generation of inhibitors against gallic acid-induced apoptosis produces different sensitivity to gallic acid,” Biol. Pharm. Bull., vol. 24, pp. 249-253 (2001). Also, theaflavin monogallates and digallates isolated from tea have been shown to inhibit cancer cell growth and induce apoptosis. See, e.g., J. Lu et al., “Differential effects of theaflavin monogallates on cell growth, apoptosis, and Cox-2 gene expression in cancerous versus normal cells,” Cancer Research, vol. 60, pp. 6465-6471 (2000); T. Ohno et al., “Cytotoxic activity of gallic acid against liver metasis of mastocytoma cells P-815,” Anticancer Res., vol. 21, pp. 3875-80 (2001); and G. Y. Yang et al., “Effect of black and green tea polyphenols on c-jun phosphorylation and H2O2 production in transformed and non-transformed human bronchial cell lines: possible mechanisms of cell growth inhibition and apoptosis induction,” Carcinogenesis, vol. 21, pp. 2035-2039 (2000). The anti-tumor promoting active constituents of the fruits of Caesalpinia ferrea were identified as gallic acid and methyl gallate. See E. S. Nakamura et al., “Cancer chemopreventive effects of constituents of Caesalpinia ferrea and related compounds,” Cancer Lett., vol. 177, pp. 119-24 (2002). Orally administered gallic acid, with and without the anti-cancer drug cisplatin, was found to cause apoptosis in lung cancer cells transplanted in mice. See M. Kawada, “Anti-tumor effect of gallic acid on LL-2 lung cancer cells transplanted in mice,” Anticancer Drugs, vol. 12, pp. 847-852 (2001).
Gallotannic acid, gallic acid, and catechin were found to cause food intake and growth depression when fed to weanling rats. See M. A. Joslyn et al., “Comparative effects of gallotannic acid and related phenolics on the growth of rats,” J. Nutrition, vol. 98, pp. 119-126 (1969). The tolerance of the rats to tannic acid depended on their initial age and weight. Older and heavier rats adjusted to tannic acid in the diet. See Z. Glick et al., “Food intake depression and other metabolic effects of tannic acid in the rat,” J. Nutrition, vol. 100, pp. 509-515 (1970). Gallic acid was found to induce a fatty liver. Tannic acid, but not gallic acid, increased excretion of nitrogen. See Z. Glick et al., “Effect of tannic acid and related compounds on the absorption and utilization of proteins in the rat,” J. Nutrition, vol. 100, pp. 516-520 (1970). Gallic acid and propyl gallate were found to suppress food intake and retard growth, with propyl gallate having a much greater effect. See Z. Glick, “Modes of action of gallic acid in suppressing food intake in rats,” J. Nutrition, vol. 111, pp. 1910-1916 (1981). In a study on mice assessing the toxicity of gallic acid, gallic acid did not affect weight of the mice at 1000 mg/kg for 28 days, but a slight decrease in food intake was noted. See K. Rajalakshmi et al., “Assessment of the no-observed-adverse-effect level (NOAEL) of gallic acid in mice,” Food and Chemical Toxicology, vol. 39, pp. 919-922 (2001). However, in a subchronic toxicity study on rats, 5% gallic acid was found to suppress body weight gain over a period of 13 wks. See N. Niho et al., “Subchronic toxicity study of gallic acid by oral administration in F344 rats,” Food and Chemical Toxicology, vol. 39, pp. 1063-1070 (2001).
U.S. Patent Application No. 2002/0068094 discloses a physiologically active extract from indigo which includes tryptanthrin, 3,5,4′-rihydroxy-6,7-m-ethylenedioxy-flavone, kaempferol, 3,5,7,4′-tetrahydroxy-6-methoxy-flavone, gallic acid, caffeic acid, indirubin, pheophorbide a, and methyl pheophorbide a. Although indicating that the extract may have many different physiological functions, experiments are discussed only to show antiseptic action, antiviral action, antitumor action, radical-entrapping action, apoptosis controlling action, and action for controlling the production of cytokine. Gallic acid was shown to have radical-entrapping action.